The present invention relates to a device for the transfer of long products, particularly metal products such as bars or tubes of circular section, and in which the products in the course of transfer are separated one from the other and displaced laterally step by step all while being propelled laterally and being rotated about their axes.
As an application, but in no way limiting of such devices, one can cite for example cooling units located at the end of a hot production line for welded or rolled metal tubes or metal bars. Such devices are used to permit the products, as they are transferred, to be cooled from the temperature of the end of the last heating operation to a temperature as close as possible to the ambient temperature in order to permit further manipulation or later treatment of the products. A temperature which is too high presents an obstacle or an inconvenience. It is important in such an application to obtain even and homogeneous cooling of the products in a manner to prevent their deformation. In effect, an uneven cooling creates warping and uneven tensions and stresses causing deformation of the products which in turn cause difficulties in the good execution of manipulation or of ultimate working of the cold products and make straightening operations necessary. As another application one could cite heat treatment installations, particularly furnaces.
One knows already of transfer devices having two sets of stringers placed parallel in the direction of advance of the product, each of the stringers having on its top surface a plurality of teeth, preferably identical, and each defined by two plane surfaces symmetrical with respect to the vertical, one of the sets of stringers being fixed and the other set of stringers being carried by a mobile chassis capable of being driven in movements of vertical translation and of horizontal translation. The products are alternately supported by the fixed stringers and the mobile stringers and by each of the displacements of the mobile stringers are thus displaced along the entire length of the stringers while turning without sliding, at intervals, about their axes. Such an embodiment although currently used in practice presents various disadvantages.
Thus during the passage of the product supported by the mobile stringers over the peaks of the teeth of the fixed stringers, it is necessary, to insure that the product does not sustain damage by the crest of the peak of these teeth. It is also necessary to raise the product by lifting movement of the mobile stringers above the level of the top of the peak of the teeth of the fixed stringers, this peak being cleared by a movement of horizontal translation of the mobile stringers, during which phase, the product no longer rotates, which constitutes a disadvantage, particularly in the case of cooling units.
Furthermore, the act of imparting to the mobile stringers successive movements of vertical translation and horizontal translation requires complex and very fragile mechanisms.
Also, one should observe that all the weight of all of the products rest alternately on the fixed stringers and the mobile stringers, this necessitating for all the stringers and their chassis good characteristics of mechanical strength thus rendering the entire device heavy and complicated.
One should also observe that the amplitude of the displacement in vertical translation of the mobile stringers must be relatively significant, especially to assure the movement of the product above the top peaks of the teeth of the fixed stringers as explained above, which likewise necessitates very complex driving mechanisms. Thus the known device creates very significant forces and high inertias, requiring increasing the necessary driving forces.